Electrotherapeutic apparatus



J. H EASTMAN.

ELECTROTHERAPEUTIC APPARATUS.

APPLICATION FILED SEPT. 22, I919.

1,3455 37 Patented July 6, 1920.

UNITED STATES PATENT OFFICE.

JAMES H. EASTMAN, 0F DETROIT, MICHIGAN.

ELECTROTHERAPEUTIC APPARATUS.

Specification of Letters Patent.

Patented July 6, 1920.

Application filed September 22, 1919. Serial No. 325,353.

This invention relates to electro-therapeutic apparatus, andhas for its object a current-regulating screw operating upon the armature.- Ordinarily these current-regulating screws change the current flow by varying the pressure between the armature contact and interrupter contact. However, a careless adjustment of this screw may either increase the pressure between the two contacts beyond the powerof the armature to break or 1' am the armature block against the pole piece, causing the apparatus to cease to function as an interrupter. Thereupon a large current flow will be permitted through the magnet coil and will burn 1t out.

The present invention is an improvement in the regulating screwand its connections so that the regulating screw is entirely 1ndependent of the circuit through the magnet coil. The maximum pressure that the magnet has to overcome in breaking a circuit is constant and may be fixed by the manufacturer.v The regulating screw operates simply to weaken that pressure and regulate the current flow. If this screw is carelessly adjusted to place too great a resistance in the circuit, the only result is the complete rupture of the circuit and the complete cessation of the current.

A further important advantage is that with my invention the gap between the armature block and magnet pole remains always constant. It can be carefully fixed by the manufacturer to secure the best tractile results from the magnet and can never thereafter be varied by adjusting the screw. These and other objects will be better under stood when the invention is described in detail.

In the drawings,.-' V

Figure 1 is a section of the box containing the interrupter and the condenser of a violet ray machine.

Fig. 2 is a section on the l1ne 22 of Fi 1. e l o Fig. 3 is a diagrammatic view of the apparatus.

The so-called violet ray machine is used for electro-therapeutic purposes. It comprises usually a magnet coil a, an armature b, an armature contact 0, an interrupter contact d, a condenser c, transformer an electrode-holder g, and anelectrode m. The,cab le h is connected up with an electric light socket (not shown) which forms a source of current. This cable contains the two usual conductors, one conductor i connecting directly with the magnet coil, the

- other conductor is connecting with the binding post j that is in contact with the armature 1). Hence part of a circuit can be traced through the magnet coil, thence through the connecting wire Z, and the binding post m, which is in electrical connection with the bracket a which carries the interrupter contact d.

Bridged across the interrupter gap is the condenser e and the primary coil of the transformer f. The wire 0 leads from the binding post of the armature to the condenser e, and the wire 29 leads from the condenser to the primary coil of the transformer, which is shown only in the diagram matic view and which is supported on the end of the cable Q '(shown in Fig. l) together with the electrode-holder g. From the primary coil of the transformer a wire 1" leads back to the binding post m and through the binding post to the interrupter contact d.. The interrupter alternately makes and breaks the -main circuit. The condenser being bridged across the gap causes thecurrent to surge back and forth across the gap, producing a current of increased voltage and high frequency. The transformer f which is ,a step-up transformer, very materially increases the voltage. The result is a current of very high frequency and high voltage in the secondary circuit of the transformer. One end of the secondary circuit 8 of the transformer is grounded by connecting it with the wire 79 of the primary circuit. The other end of the secondary circuit is connected to the electrode-holder g. This is ordinarily connected with the glass vacuum electrode 00. This electrode when placed in contact with the body discharges numerous sparks between the electrode and the body, which gives it its name-violet ray apparatus. This much of the apparatus is old.

Heretofore the interrupter contact at has been in the form of a screw which can be turned farther in to increase the pressure between the armature contact 0 and the interrupter contact d and increase the amount oi current by decreasing the resistance, or turned farther out to lessen the pressure of the armature contact 0 upon the interrupter contact d and decrease the amount of current. The trouble with this form of adj ustment is that if the screw is turned in too far the armature b will be jammed up against the magnet pole t. The magnet and armature will then cease to function as an interrupter. A'continuous current will then flow around the magnet and burn the magnet out. In fact, this adjustment of the current-regulating screw does not have to be such as toj am the armature block against the pole of a magnet. If the current-regulating screw is turned far enough in to bend the armature so that its pressure against the ipterrupter contact is great, then the strength of the magnet will not be sufficient to attract the armature and there will be no breaking of the circu it. A continuous current will flow around the magnet, the resistance of the coils heating up the wire, and the windings will burn out in short order. These are very serious conditions in apparatus of this kind, which do not occur in an ordinary interrupter, for the ordinary interrupter contact screw is not used as a screw to vary the amount of the current flowing through the apparatus but is given a permanent adjustment usually with the jam nut, with very little likelihood of its getting out of this adjustment. In electro-therapeutic apparatus the pressure of the armature upon the contact is used as a means of regulating the current flow and consequently the position of this screw is being constantly varied by the patient or the operator.

It is the object of the present invention to make the possibility of a continuous flow of current through the magnet practically impossible and insure against burning out notwithstanding the adjustment of the pressure of the armature upon the interrupter contact is used as a regulating means for adjusting the current flow. It is a further object to always have a uniform gap between the armature block and the pole of the magnet. lVith the current regulating accoi'nplished by the interrupter contact screw, as heretofore, obviously every time the pressure of the armature upon the screw is adjusted the gap between the magnet and armature block is varied.

Instead oi? an adjustable interrupter contact a stationary contact (Z is provided, the gap between the armature block and the pole t always remaining constant. The pressure of the armature upon the interrupter contact (Z is varied by providing an arm a that is attached to the armature at right angles thereto between the point where the armature contacts the pole t and the point where the armature is supported. Through the top of the box is threaded an adjusting screw 0, the end of which can engage against this arm a. N o matter how far this screw o is screwed in, a continuous current will not flow through the magnet, for it the arma-- ture is jammed up against the end of the pole t so that the devices cease to function as an interrupter, then the circuit through the armature and interrupter contact (6 is broken. If the adjusting screw (Z is screwed out of the box until out of contact with the arm a, then the pressure between the armature and the interrupter contact is at its maximum, but the armature continues to function as an interrupter so no continuous current around the magnet is possible and the magnet cannot be burned out.

A very material advantage of this improvement is that, as already explained, the gap between the armature block and pole piece always remains constant, and further, the maximum pressure can be established by the manufacturer and can never be varied by adjustment. Hence the manufacturer may set the armature and the interrupter contact in such a position that the maximum pressure will never be greater than is possible for the magnet to break the contact. Hence the apparatus can never cease to function by reason of improper adjustment and burn out the coil. The only error in adjustment that can happen is the screwing of the current-regulating screw to a point where the armature ceases to contact with the interrupter contact. Then the effect is simply to permanently break the circuit and stop all current flow.

The arm it affords the additional function of steadying the armature. It has a definite period of vibration, While the armature ordinarily does not. The two being constrained by their connection to move together, this definite period of vibration is in a large measure impressed upon the armature so that the periods of vibration of the armature are more nearly uniform than would otherwise be the case.

IV hat I claim is:

1. In electro-therapeutic apparatus, the combination of a magnet coil, an armature intermittently attracted thereby, an interrupter contact engaged intermittently by the armature, all said devices being in circuit, an arm secured to the armature between its point of support and the interrupter contact, and means for increasing the pressure against the arm to varyingly weaken the pressure of the armature against the interrupter contact. j

2. In electro-therapeutic apparatus, the combination of a magnet coil, an armature intermittently attracted thereby, an interrupter contact with which the arn'lature intermittently engages, all said devices being in circuit, an arm secured to the armature at an angle thereto and between the armature point of support and the interrupter contact, and a screw for increasing the pressure on the arm to varyingly weaken the pressure of the armature against the interrupter contact.

3. In electro -therapeutic apparatus, a magnet coil, a spring armature intermittently attracted by the magnet, an interrupter contact adapted to be intermittently engaged by the armature, all said devices being in circuit, and adjustable means independent of the said circuit for increasing the pressure against only one side of the armature between the point of support and the interrupter contact to varyingly weaken pressure against only one side of the saidarm to varyingly weaken the maximum natural spring pressure between the armature and the interrupter contact.

In testimony whereof I affix my signature.

JAMES EASTMAN. 

